Carbureter.



J. C. HOUGHTON & L. A. HILL.

CARBURETER.

APPLICATION FILED DEC. 7.1914.

1 16 1 093, Patented Dec. 14, 1915.

4 SHEETSSHEET I.

J. c. HOUGHTON & L. A. HILL.

CARBURETER.

APPLICATION FILED 050. 7.1914.

Patented Dec. 14, 1915.

4 SHEETS-SHEET'Z.

l m m "m ll. I IHI/ u 1 4 r W w mum 5% J. C. HOUGHTON & L. A. HILL.

CAHBURETER.

APPLICATIONFILED DEC. 7. I914. 1,164,09. Patented De0.14,1915.

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JAMES C. HOUG-HTON AND LQUIS A. HILL, OF WASHINGTON, DISTRICT OFCOLUMBIA.

CARBURETER.

Specification of Letters Patent.

Patented Dec. M, was.

.Application filed December 7, 1914. Serial No. 875,846.

To all whom it may concern:

and LOUIS A. HILL, citizens of the United States, residing atVashington, in the'District of Columbia, have invented certain new anduseful Improvements in Carbureters; and we do hereby declarethe'following to be a full. clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

, This invention relates to certain new and useful improvements incarburetors for producing an explosive mixture of liquid hydrocarbon andair for use in internal-combustion engines.

The primary object of this invention is the production of a carbureterin which the liquid fuel fed from any suitable source of supply isforced from a float feed reservoir and commingles with the air supplyunder a degree of pressure which is predetermined, and automaticallycontrolled, so as to present at all times a charge of liquid fuel inexcess of the actual demands of the engine in connection with which thecarbureter is used.

Another object of this invention is the production of means forpositively delivering the liquid fuel into the air supply underpressure, said means being preferably located between the float feedreservoir and the point of discharge, and'entirely sub merged within theliquid fuel.

A further object of the present invention is the production of meanswhereby any liquid fuel which may be pumped in excess of the momentaryrequirements of the engine may be automatically returned to the floatfeed reservoir. This means consisting of a variable pressure regulatingor by-pass valve located between the float reservoir and the point offuel discharge, and capable of automatic control in conjunction with theair controlling or throttle valve.

A still further object of this invention is the production of meanswhereby the throttle or air controlling valve, the variable pressureregulating valve, and the relative throw of the-operating throttle levermay be inclependently and separately adjusted without disturbing anyothen adjustment already made.

A further object is the provision of means whereby the conditions ofpartial vacuum existing in the engine manifold and the float feedreservoir are equalized at all times.

With these and other objects and advantages in view the presentinvention consists in the novel arrangement and combination of partshereinafter particularly described vand pointed out in the claimsfollowing.

In the accompanying drawings which form part of this application forLetters Patent, and whereon corresponding reference characters indicatelike parts in the several views: Figure 1 represents in side elevationthe improved carbureter completely assembled. Fig. 2 is a top plan viewthereof. Fig. 3 is a central vertical section of the invention, taken onthe line 33 of Fig. 2. Fig. 4 is a top plan view of the carburetor withthe cover section leading to the manifold of the engine, removed. Fig. 5is a horizontal sectional view on the zig-zag line 5-5 of Fig. 3. Fig. 6is a vertical transverse sectional view on the line 66 of Fig. 2. Fig. 7is a fragmentary detail view showing in vertical section thefloat-controlled fuel feed supply. Fig. 8 is a vertical transversesectional view taken on the line 88 of Fig. 4. Fig. 9 is a detail viewof the variable pressure regulating valve detached. Fig. 10 is also adetached view showing in side elevation an arm for actuating thethrottle valve, being a reverse view of the same arm as shown in Fig. 1.Fig. 11 is an enlarged sectional detail view of the adjust ableconnection for the throttle valve, indicated on the line 11-11 ofFig. 1. Fig. 12 is a detail view in side elevation of the air throttlevalve detached. Fig. 13 is also a detail vertical sectional view throughsaid valve. Fig. 14 is a detail horizontal sectional view of thethrottle valve shown by Figs. 12 and 13, and, Fig. 15 is a fragmentarydetail sectional view on the line 1515 of Fig. 1, showing the adjustableconnection between the throttle valve and the variable pressure valve,whereby the throw of the said throttle lever may be adjustedindependently of the said valves.

The preferred embodiment of this invention contemplates and includes afloat feed supply reservoir, a pressure chamber containing a submergedpump capable of supplying liquid fuel in excess of the demands of theengine, a variable pressure regulating valve for permitting the returnof said excess fuel into the supply reservoir, and

means for automatically actuating the pressure regulating device inconjunction with the throttle valve of the carbureter.

' Reference being had to the drawings and characters thereon, it will beseen that the carbureter comprises a casing 1 provided with a suitableflanged'cover 2 secured thereon, which cover is in turn adapted to besecurely attached to the manifold or other part of aninternal-combustion engine by bolts or other securing means, not shown.Located within this casing 1 are the float reservoir 3, the pressurechamber 4, and the chamber 5 in which latter the air throttle valve ispositioned, and in the upper end of which is provided the mixing chamber6. Within the float reservoir 3 is located a float 7 of hollow metalconstruction, cork or other buoyant material suitably fastened to oneend 8 of a pivoted lever 9. This float is secured to its lever 9 bymeans of a retaining screw 10, or it may be otherwise attached.

and by preference the said lever is formed I from a strip of sheet metalbent to the desired shape, as shown by Fig. 5, and bifurcated at itspivotal end 11 to engage collars 12 carried by the stem 13 of avertically movable needle valve 14. The inner end 15 of a perforatedplug 16 forms the guide and seat for this Valve 14, the said inner endbeing also provided with lateral openings 17 for the admission of fuelwhen the needle valve is ,opened. lVithin this perforated plug 16 isprovided a suitable straining device 18 held in place by the cap 19 towhich is secured the usual fitting 20 for connection with the source offuel supply. The needle valve 14 is provided with a spring 21surrounding'its stem 13, the function of this spring being to partiallycounterbalance the float t and assist in seating said valve, and to keepit seated at all times except when the fuel-1evel in reservoir 3 dropsbelow the prearranged so-called constant level. And

by reference to Fig. 7 it will be noted that said valve and itscooperating parts may be readily adjusted or removed and replaced,

as occasion requires, throu h removal of the cap nuts 22 and 23; the oat7 and needle valve 14 aforesaid operating in the usual and wellunderstood manner to insure at all times a supply of liquid fuel withinthe float feed reservoir 3, and maintain it at practically a constantlevel.

The pressure chamber 4 hereinbefore referred to is located below thefloat reservoir 3, and intermediate of these is a pump casing containinga submerged pressure pump 24. This chamber 4 lies between the bottom ofthe carbureter casing 1 and a recessed plate 25 forming the body of saidpump casing, while a superimposed plate 26 constituting a cover for thiscasing serves to in close the pressure pinup 24 of rotary type. Theplate 25 is secured to an annular shoulforming the pump casing. The pumpgear 31 is similarly provided with a stub shaft 36 having a suitablebearing 37 in plate 25, and an extended shaft 38 having a full lengthbearing 39 in the plate or pump cover 26. To the upper end of said shaft38 is secured a bevel gear 40 meshing with a similar gear 41 secured toa driving shaft 42, which latter projects into the carbureter casing 1through a removable bearing 43 aflixed to said casing.

To the projecting end of shaft 42 power is applied from any suitablesource. That is to say, this power may be derived from the engine itselfand transmitted to the pressure pump, or it may be derived from anindependent source such as a separate motor under control of theoperator. For the purposes of this invention it is sufficient to saythat power is applied to this shaft 42, and that 1t in turn impartsmotion to the pump which always supplies fuel in excess of requirementsof the engine; and, while a form of rotary gear pump is herein shown anddescribed it Will be understood that any other suitable pumping meansmay be employed within the casing, provided'it is situated below theconstant liquid level.

In practice, the liquid fuel when pumped from the float reservoir 3.into pressure chamber 4 passes through a conduit 44 formed by thecutaway portions 45 and 46 in the pump casing plates 25 and 26,respectively, as shown by Figs. 4, 5 and 8 of the drawings. This conduit44, as shown by Fig. 8, extends beneath the plate 26 and directly intothe path of travel of the pump gears 30 and 31, the liquid fuel beingthereby caught and forced onward by the teeth of said gears, rotating asaforesaid within the circular chambers 47 and 48 of the pump casing asshown by Fig. 5. Upon leaving the pump casing the liquid fuel passesthence through an opening or port 49 into the pressure chamber 4beneath, and it will be noted that the location and contour of theseveral passages and conduits leading to and from the pressure pump asaforesaid are designed, arranged and adapted to facilitate the rapid,eflicient and forcible delivery of the liquid fuel under all conditions.

The variable pressure regulating valve designed to operate between thefloat reservoir 3 and the pressure chamber 4 will now be described:Referring particularly to Figs.

5, 8 and 9, this ialve consists of a stand-pipe or tube 50 secured toand rising from the plate or cover 25 of the pump casing by means of thescrew-threaded connection 51. This pipe or tube 50 is in directcommunicze tion with the interior of pressure chamber 4 and rises withinthe float reservoir 3 to a point above the constant liquid fuel level. Aflanged valve is seated upon the upper end of this pipe or tube 50. andis adapted to be opened by the return of excess liquid fuel frompressure chamber 4'. or may be closed by the action of a spring underC011- trol of the air throttle valve. as will later appear. This valve52 is secured to one end of a valve lever 53 pivoted at 54 upon a fixedsupport which latter inturn is secured to a base block 56 by screw 57.The said block 56 also serves as a stop for one end of the valve lever53.'thereby limiting the opening of valve 52. as shown by Figs. 8 and).tension spring 58 is secured to the lever 53 and also to the end of an.arm 59 projecting from a rock-shaft ()0 through which the tension ofsaid spring is controlled.

The shaft 60 to which said arm 59 is attached is journaled in a tubularsleeve 61- threaded into the side of casing 1, as best. shown by Fig. 8.while the outer end of this same shaft (30 is provided with a dependingarm 62 (see Figs. 1 and 8) having a reduced or cut-away portion 63, andan opening 6% for the reception of an eccentrically mounted adjustingthumb nut 65. .This thumbnut is provided with a knurled head 66 thenotches of which are engaged by a tooth upon spring 67 adapted to retainsaid nut in any of its adjusted positions. The eccentric portion 68 ofthis thumb nut operates within the corresponding opening (34, and whenturned causes the depending arm 62 to rock slightly, thereby turningshaft 60 with its arm 59, and regulating the variable tension of spring58 which is to be overcome whenever thevariable pressure regulatingvalve 52 is lifted. The thumb nut 65 is held within the reduced portion(33 of depending arm 62 by a screw 69 upon which said nut is mountedeccentrically, this same screw 69 also serving to secure said dependingarm 62 to a lever 70 mounted upon the shaft 60. This lever 70 isprovided with a slot 71 adapted to receive an enlarged portion 72 uponscrew 69 thereby contributing to the ready and exceedingly fineadjustment of depending arm with relation to the lever 70. The saidlever 70 is pivotally connected at 73 ton link 74, which link in turn isconnected with the main controlling lever of the air throttle valve.Thus it will be seen that an initial adjustment of the carbureter-canreadily be effected by moving thumb-nut ()5 thereby relativelyincreasing or decreasing the tension of spring 58 to which valve 52 isoperatively connected. This adjustment may be made.independently of thethrottle lever and when so made the variable pressure regulating valve52 will be permitted to open more or less according to varying speed andload requirements, while returning to reservoir 3 excess quantities ofliquid fuel from the pressure chamber 4.

The throttle valve to which the variable pressure regulating valve 52 isconnected by means of the link 74 will now be described. This feature ofinvention located within chamber 5 of casing 1, comprises outer andinner sleeves 75 and 76, respectively, retained in position by means ofrecessed portions 77 formed in the bottom of chamber and a flange 78upon sleeve 76 extending into an annular recess 79 formed in the upperpart of said chamber 5, as shown by Figs. 3 and 6. The outer sleeve 75of this throttle valve is adapted to oscillate about the inner sleeve 76which is nonrotatable, and by reason of this oscillatory movement of theouter sleeve upon and about the said inner sleeve certain ports in bothof said sleeves are brought into and out of register for the purpose ofproducing a proper mixture of liquid fuel and air. The outer sleeve 75is provided with ports or openings 80 (see Figs. 12 and 14) ofapproximately triangular contour, the hypotheneuse 81 of which is curvedsubstantially as shown by Fig. 12. The purpose of so forming these portsor openings 80 is to insure a gradual increase'in the admission of airused in the explosive mixture, the dotted lines in Fig. 12 indicatingthe relative position of ports in the inner sleeve 76 when the engine isthrottled down to slow speed, the finer adjustment hereinbeforedescribed depends, of course, upon atmospheric and other conditions wellknown in the art to which this invention belongs.

So far as concerns the air throttle valve, however. it is obvious thatoscillation of sleeve 75 to the left as indicated by the arrow in Fig.12', gradually uncovers the ports of the, inner sleeve 76 to admit agradually increasing quantity of air thereby producing a very etficientmixture; registration of these ports being complete when the valve isfully open to admit the maximum quantity of air for high speeds.

The inner sleeve 76 of the air throttle valve is provided with openings83 formed by channel shaped members S-l each comprising side walls 85and upper constricted ends 86. as shown by Figs. 6. 13 and 14. Theseupper ends are angular-1y disposed and serve to direct the air. incurrents. to the center of the structure. and directly into the path ofthe liquid fuel. Centrally positioned within the sleeves T5 and 76 is afuel jet-tube 87 having an outlet nozzle 88 of conical or constrictedformation for delivcontrol of the operator.

ering a forced feed or stream of liquid fuel, and thoroughly comminglingsame with the several streams of air, or air jets discharging into thesame path immediately above. The said liquid fuel discharge tube 87 isconstructed and arranged to be readily screwed into the dependingportion 89 of the carhureter casing 1, thereby providing for its readyremoval for purposes of cleaning, and for such other purposes asoccasion may require. \Vhile immediately below is provided a pet cock 90for purposes of draining, and for obtaining a supply, of liquid fuel forother useful purposes. The liquid fuel in passing from the pressurechamber 4 through the conduit 91 is at all times under a head orpressure which exceeds the demands of the engine, but because of. theinterconnection between the air throttle control and the variablepressure regulating mechanism hereinbefore described, only so much ofthe liquid fuel as may be required is actually utilized, the remainderbeing automatically forced back or returned into the float feedreservoir 3, by way of the valve 52. 1

The mechanism for regulating and controlling the admission of airprimarily into and through the inlet port 92, guarded by the airthrottle valve aforesaid, comprises a bevel segment 93 secured to theouter sleeve 75 (Figs. 5, (5 and 12), constantly meshing with a similarsegment 94 formed on the inner end of a sleeve 95 journaled around shaft90, and held therein by a-pin' T. In the opposite or outer end of thissame sleeve 95 is a recess or notch 98 (Figs. 5 and 11) adapted toreceive a key or lug 99 formed upon the inner end of an arm or lever100. Secured to this arm or lever 100, and relatively adjustabletherewith, is the main operating lever 101 to the end of which isfastened a rod (not shown) leading to a suitable hand lever (not shown)under This lever 101 is adjustably secured to the said arm by meanssimilar to that hercinbefore described in connection with the variablepressure regulating valve and its operative connections. That is to say.a knurled thumb nut 102 is provided within a recessed portion 103 ofthrottle lever 101. the same being adjustably held in position by theengaging tooth oi a spring 104 (see Figs. 1 and 11). Furtlltl'll'lOl'Q.an eccentric 105' is positioned within an opening of corresponding shapein throttle lever 101. This eccentric is formed integral with thethumb-nut 102, and is held eccentrically within the said level-1 01 byscrew 100.

A collar 10? is provided on this screw 106 and operates in slot 1%formed in the arm 100. thereby providing for the relative movement ofsaid arm 100. and the throttle lever 101. when the thumb-nut 102 isturned one way or the other. \Vhen this nut is turned it will be seenthat the movement of the arm 100 transmits movement .therough theengaging lugs to the throttle valve sleeve 75 by agency of the segmentalrack or gear 93, thereby effecting an independent movement of saidthrottle valve sleeve and'its airadmitting ports either increasing ordecreasing the amount of air admitted. )Vhile this adjustment is beingmade the throttle lever 101 remains stationary. After this adjustmentthe throttle lever 101 may be operated in the usual manner.

The throttle lever 101 as shown by Figs. 1 and 10 ispreferably ofarcuateformation. the are about which this lever is constructed being struckfrom substantially the pivotal connection between the link 74 and arm 70forming part of the -variable pressure regulating mechanism heretoforedescribed. By this arrangement and interconnection of parts it will beseen that an independent adjustment regulating the throw of the throttlelever can be effected without in any manner disturbing the independentadjustments previously given the variable pressure-regulating valve andthe throttle valve.

The adjustment of the throttle mechanism is effected by means of thefollowing construction. in which 110 represents the adjustable pivotalconnection between link 74 and the throttle lever 101. Upon the latterlever 101 is mounted a traveling nut 111 through which a relativelyfixed feed screw 112 passes. A stud 113 is provided on the nut 111. intowhich a fastening screw 114 is threaded. .Between the head of this screw114 and a washer 115 a flanged bushing 116 is provided, and upon thisbushing is pivotally mounted the end 117 of link 74 (see Fig. 11) forpivotally connecting the throttle lever 101 with the depending arm orlever 70 of the variable pressure regulating valve before described.Thus it will be seen that as the nut 111 is fed along the screw 112 thepivotal connection 110 will be moved within the arcuate slot 118 oflever 101 (see Fig. 1), this movement of said traveling nut 111 andoperative connections being efl'ected by manipulation of the knurledhead 119 upon the feed screw 112 (see Fig. 15). The said feed screw 112is mounted in a bearing formed in a stud 120 carried by the lever 101.and is held against longitudinal movement by a set screw 121 whichenters an annular groove 122 formed in the screw between collars orshoulders 123 and 124. This set screw also secures in place the saidstud 120. as well as a tension spring 125 adapted to engage the knurledhead of the set screw 121. as best shown by Figs. 10 and 15. In thiscorrelative arrangement and combination of parts it will be obvious thatan. independent adjustment can readily be given the actual range of thethrottle valve conmeapoa nections, without in the least disturbing thoseof the variable pressure regulating valve and its connections.

In the cover section 2 of the carbureter there is provided a large openduct 126 as shown by Fig. 3, leading into or adjacent to the inletmanifold of the engine, the purpose of which is to establishcommunication at all times between float chamber 3 and the mixingchamber 6 adjacent to the said inlet manifold, thereby alwaysmaintaining a balance of pressure in said float chamber and mixingchamber, regardless of whether such pressure be atmospheric or partialvacuum varying in accordance with the speed of the motor and otherconditions.

It is obvious that the liquid fuel has two outlets from pressure chamber4, one by way of fuel discharge tube 87 and conduit 91; and the other byway of pressure regulating valve into fuel reservoir 3, the latter flowbeing more or less restricted by the tension of spring 58, which tensionin turn is regulated by the controlling throttle and intermediateconnections. It will also be apparent that the return to reservoir 3 ofexcess fuel by way of pressure regulating valve 52 as aforesaid, wouldbe influenced by pressure conditions upon opposite sides of pressurechamber 4 unless equalizing means such as duct 1'26 was provided.

It is well understood that carbureters ordinarily depend upon a partialvacuum in the engine manifold induced by suction of the engine pistonsto produce a flow of liquid fuel. As a consequence the delivery of bothfuel and air and the mixture of these two elements ordinarily fluctuatesunder influence of varying barometric'and temperature conditions, and toovercome this dii'liculty the said equalizing duct 126 has beenprovided. Thus the liquid fuel supply is mechanically and positivelycontrolled by means of pump 24: and its cooperating pressure regulatingvalve 52, and is uninfluenced by partial vacuum conditions which areequalized in the inlet manifold and the float chamber 3.

The foregoing being a description of the present invention in the bestform of construction at present known to us, the practical operation maybe briefly stated to be substantially as follows: Liquid fuel from thefloat feed or supply reservoir 3 is forced through the rotary pump intothe pressure chamber 4 beneath, thence up through fuel-jet tube 87 andout of its constricted nozzle 88 in an exceedingly fine stream. Anexcess amount of fuel is at all times supplied to the tube 87, but byreason of the constricted formation of its nozzle 88 only apredetermined quantity thereof is used, the remainder being returnedfrom pressure chamber 4 to the feed supply reservoir 3, by way of thevariable pressure regulating valve 52 the operation whereof has beenheretofore described.

\Vhen the carbureter is set and adjusted as shown by the drawings, themixture produced will be sufficient to barely keep the engine running atslow speed, the air which is admitted through the throttle valve, andthe liquid fuel which is forced through nozzle 88, as aforesaid, beingmost effectually mixed, presented thence to the manifold, and finally tothe cylinders of the engine.

The operation of the several parts shown in the drawings, when it isdesired to speed up, is substantially as follows: The means connected tothe throttle lever 101 and under control of the operator, is firstmanipulated in the usual manner, the throttle lever 101 being therebyswung at its upper end in the direction indicated by the arrow inFig. 1. When this takes place the throttle valve sleeve equipped withthe beveled segment 93 is rotated by agency of the key or lug 99 uponthe inner end of arm 100, i

the sleeve 95, and the driving segment 91 carried by said sleeve andalways intermeshing with the driven segment 93 aforesaid. As thethrottle lever is further moved the said outer sleeve 75 is movedcorrespondingly, its triangular ports 80 being thus gradually butpositively brought into register with ports 83 of the relatively fixedinner sleeve 76, until the full port is opened and the highest speed forthe given adjustment obtained.

The adjustment illustrated in the accompanying drawings (see Fig. 1particularly) provides for no movement of the variable pressureregulating mechanism when the pivoted lever 101 is swung to open the airthrottle; that is to say in this adjustment no movement is transmittedto depending arm 70 through the interconnecting link 71, for the reasonthat the pivotal connection 110 of said link 74: with the lever 101 isthen in exact alinement with the pivot about which said throttle lever101 swings. Nevertheless, the variable pressure regulating valve 52,having previously been set by its independent adjustment heretoforedescribed, will operate against the action of spring 58 as the pressurein the pressure chamber 4 returns the excess of liquid fuel over andabove that forced through the nozzle 88 and utilized. Under theseconditions, however, it will be seen that valve 52 acts uniformlyagainst the tension of its spring. Assuming now that the traveling nut111 has been adjusted in the arcuate slot 118 thereby bringing thepivotal connection 110 out of alinement with the pivot upon wl ich thethrottle lever 101 is-mounted, it will be readily seen that as saidlever is swung at its free end in the direction of the arrow, link 74will be correspondingly moved more or less according to its selectivelocation 1n 13o said arcuate slot 118 thus imparting to the dependingarm 70 of the variable pressure regulating mechanism a correspondingmovement to increase the tension upon the variable valve spring 58,further restricting the passage of liquid fuel through said valve .52.Continued movement of said throttle lever 101 will. now serve togradually increase the tension upon spring 58 thereby requiring greaterpressure in pressure chamber 4 for the return of excess fuel toreservoir 3.

The proper forcing power of the actuating pump being predetermined itwill be observed that as the variable pressure regulating valve 52 isheld more nearly seated a greater quantity of liquid fuel will be sentthrough the nozzle 88 into a correspondingly increased quantity of air,thus producing an ellicient and very economical working mixture. Andwhen desired, an in dependent adjustment as before described, may begiven both the variable pressure regulating valve, and the throttlevalve for controlling the air supply, without disturbing the relativelyfixed movements of the throttle valve interconnected with the variablepressure regulating valve.

Having thus described our invention, that which we now claim and desireto secure by Letters Patent is:

1. A carbureter including in combination a source of fuel supply, an airinlet, a fuel reservoir, means connected with said reservoir for forcingliquid fuel in quantities ex ceeding that actually presented to the airsupply, and means interconnected with the throttle for returning andregulating the return of such excess of liquid fuel to the reservoir.

2. A carbureter including in combination a source of fuel supply, an airinlet, a fuel reservoir, a pressure chamber communicating with saidreservoir, means located between said float feed reservoir and pressurechamber for forcing the liquid fuel to its point of utilization, andmeans interconnected with the throttle for returning and regulating thereturn of such excess of liquid fuel to the reservoir.

3. A carbureter including in combination a source of fuel supply, an airinlet, means including a power driven rotary pump for forcing liquidfuel into the air supply, and a. pressure regulating valve for returningsuch excess of liquid fuel to the reservoir.

4. A carbureter including in combination a source of fuel supply, an airinlet, a fuel reservoir, a pressure chamber communicating with saidreservoir, and means including a pump submerged beneath the liquid fuellevel in said reservoir for forcing liquid fuel into the air supply, andregulable means interconnected with the throttle for returning to saidreservoir the excess quantities of liquid fuel not forced into the airsupply.

5. A carbureter including in combination a source of fuel supply, an airinlet, a fuel reservoir, a pressure chamber communicating with saidreservoir, means for forcing liquid fuel through the pressure chamberinto the air supply, and regulable means interconnected with thethrottle located between the said reservoir and pressure chamber forreturning the excess quantities of liquid fuel not forced into the airsupply.

6. A carbureter including in combination a source of fuel supply, an airinlet, a fuel reservoir, a pressure chamber communicating with saidreservoir, means for forcing liquid fuel through the pressure chamberinto the air supply, and means located between said fuel reservoir andpressure chamber including a variable pressure regulating valve forreturning the excess quantities of liquid fuel not forced into the airsupply.

7. A carbureter including in combination a source of fuel supply, avalve-controlled air inlet, a fuel reservoir, a pressure chambercommunicating with said reservoir, means for forcing liquid fuel throughthe pressure chamber into the air supply, and

means located between said fuel reservoir and pressure chamber mcludinga variable pressure regulating valve for returning the excess quantitiesof liquid fuel not forced into the air supply.

8. A carbureter including in combination an air inlet, a nozzle, arotary throttle valve consisting of inner and outer sleeves havingregisterable ports formed therein, channelshaped air-directing membersconverging toward said nozzle from the ports of said inner sleeve, andmeans for operating said throttle valve.

9. A carbureter including in combination an air inlet, a nozzle, arotary throttle valve consistin of inner and outer sleeves havingregistera le orts formed therein, channelshaped airirecting membersconverging toward said nozzle from the ports of said inner sleeve andhaving constricted upper ends, and means for operating said throttlevalve.

10. A carbureter including in combination an air inlet, a nozzle, arotary cylindrical throttle valve consisting of relatively fixed andmovable inner and outer sleeves having registerable ports formedtherein, channelshaped air-directing members converging inwardly fromthe ports of said inner sleeve and having constricted and angularlyarranged upper ends adapted to centrally focus upon said nozzle, andmeans for manually operating said throttle valve.

11. A carbureter including in combination a source of fuel supply, anair inlet, a reservoir, a pressure chamber connnunicating with saidreservoir, means for forcing liquid fuel through said pressure chamberinto the air supply, a variable pressure regulating valve locatedbetween the said reservoir and pressure chamber, means for controllingthe air inlet, and means for interconnecting the variable pressureregulating valve with means for controlling the admission of air.

12. A carbureter including in combination a source of fuel supply, avalve controlled air inlet, a reservoir, a pressure chambercommunicating with said reservoir, means located between the reservoirand pressure chamber for forcing liquid fuel through said pressurechamber into the air supply, a variable pressure regulating valvelocated between the said reservoir and pressure chamber, and meansinterconnecting a valve controlling the air inlet with the variablepressure regulating valve whereby pressure,

in the pressure chamber will be automatically controlled in returning tothe said reservoir the excess of liquid fuel.

13. A carbureter including in combination a source of fuel supply, anindependently adjustable valve controlled air inlet, a reservoir, apressure chamber communicating with said reservoir, means locatedbetween said reservoir and pressure chamber for forcing liquid fuelthrough the pressure chamber into the air supply, a variable pressureregulating valve between said reservoir and pressure chamber capable ofindependent adjustment With relation to the valve controlled air inlet,means interconnecting said variable pressure regulating valve with thevalve controlled air inlet capable of independent adjustment withrelation to both of said valves, and means for operating said air inletvalve.

14. A carbureter including in combination a source of fuel supply, afuel reservoir, means connected with said reservoir for forcing liquidfuel into the air supply, and regu-lable means for returning to saidreservoir excess quantities of liquid fuel not forced into the airsupply, and an equalizing duct connecting said fuel reservoir above itsfuel level with the mixing chamber of the carbureter, whereby pressureconditions in the fuel reservoir and mixing chamber are equalized.

15. A carbureter including in combination a source of fuel supply, afuel reservoir atmospherically sealed, means connected with saidreservoir for forcing liquid fuel into the air supply, regulable meansfor returning to said reservoir excess quantities of liquid fuel notforced into the air supply, and an equalizing duct connecting saidreservoir above its fuel level with the mixing chamber of thecarbureter, whereby pres sure conditions in said fuel reservoir andmixing chamber are instantly equalized.

In testimony whereof we aflix our signatures, in presence of twosubscribing witnesses.

lVitnesses THOMAS DURANT WM. E. DYRE.

